Riakc_pb_pool is a project mainly written in Erlang, it's free.
A protocol buffer pool for riak
A storage pool client for riak using protocol buffers, where you can specify your client_id as part of a put / get / etc. request, which will help prevent you from overflowing your vector clock buffer.
ClientId = riakc_pb_pool:make_client_id({self()}). Object = riakc_obj:new(<<"groceries">>, <<"mine">>, <<"eggs & bacon">>).
riakc_pb_pool:put(ClientId,Object).
riakc_pb_pool:get(123,<<"groceries">>, <<"mine">>).
riakc_pb_pool:delete(123,<<"groceries">>, <<"mine">>).